• Restorative Dentistry and Endodontics
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• v.43 no.1
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• pp.3.1-3.10
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• 2018

Objectives: The aim of this study was to compare root canal volume change and canal transportation by Vortex Blue (VB; Dentsply Tulsa Dental Specialties), ProTaper Next (PTN; Dentsply Maillefer), and ProTaper Universal (PTU; Dentsply Maillefer) nickel-titanium rotary files in curved root canals. Materials and Methods: Thirty canals with $20^{\circ}-45^{\circ}$ of curvature from extracted human molars were used. Root canal instrumentation was performed with VB, PTN, and PTU files up to #30.06, X3, and F3, respectively. Changes in root canal volume before and after the instrumentation, and the amount and direction of canal transportation at 1, 3, and 5 mm from the root apex were measured by using micro-computed tomography. Data of canal volume change were statistically analyzed using one-way analysis of variance and Tukey test, while data of amount and direction of transportation were analyzed using Kruskal-Wallis and Mann-Whitney U test. Results: There were no significant differences among 3 groups in terms of canal volume change (p > 0.05). For the amount of transportation, PTN showed significantly less transportation than PTU at 3 mm level (p = 0.005). VB files showed no significant difference in canal transportation at all 3 levels with either PTN or PTU files. Also, VB files showed unique inward transportation tendency in the apical area. Conclusions: Other than PTN produced less amount of transportation than PTU at 3 mm level, all 3 file systems showed similar level of canal volume change and transportation, and VB file system could prepare the curved canals without significant shaping errors.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.195-203
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• 2004

VolumePro is a real-time volume rendering hardware for consumer PCs. However it cannot be used for the applications requiring perspective projection such as virtual endoscopy since it provides only orthographic projection. Several methods have been presented to approximate perspective projection by decomposing a volume into slabs and applying successive parallel projection to thou. But it takes a lot of time since the entire region of every slab should be processed, which does not contribute to final image. In this paper, we propose an efficient perspective projection method that makes the use of several sub-volumes with cropping feature of VolumePro. It reduces the rendering time in comparison to slab-based method without image quality deterioration since it processes only the parts contained in the view frustum.

• Transactions of Materials Processing
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• v.13 no.4
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• pp.350-358
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• 2004

The effects of alloying elements on microstructural features and mechanical properties in 0.55%C medium carbon steels were investigated. The samples were austenitized at 105$0^{\circ}C$ for 30min. followed by quenching in a salt bath in the temperature range of 500 ~ $620^{\circ}C$. The addition of Cr resulted in the decrease of the volume fraction of pro-eutectoid ferrite and interlamellar spacing in pearlite and the increase of strength. However, the addition of B caused the increase of the volume fraction of pro-eutectoid ferrite. Reduction of area and Charpy impact values were influenced by the combined effect of microstructural features, such as the volume fraction of pro-eutectoid ferrite, interlamellar spacing and the thickness of lamellar cementite in pearlite.

• Journal of Veterinary Clinics
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• v.30 no.3
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• pp.151-158
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• 2013

This study aimed to evaluate the plasma concentration of NT-proBNP in dogs with different stages of heart failure by chronic mitral valve insufficiency (CMVI). Fifty small-breed dogs with CMVI and 7 healthy control dogs without cardiac disease and critical systemic diseases were included in the study population. As a preliminary study, we compared the plasma concentrations of N-terminal pro-brain natriuretic peptide (NT-proBNP) and the echocardiographic parameters between dogs of the International Small Animal Cardiac Health Council (ISACHC) classes. Then, we evaluated the associations between NT-proBNP and echocardiographic parameters. Plasma NT-proBNP levels showed a significant difference among the ISACHC groups. In the comparison between echocardiographic parameters and NT-proBNP, NT-proBNP were found to be associated with left atrium/aorta (LA/AO), early diastolic transmitral flow (E) velocity, late diastolic transmitral flow (A) velocity, end diastolic volume index (EDVI). Our study found plasma NT-proBNP might be useful to predict the disease progression in dogs with CMVI.

• Membrane Journal
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• v.22 no.5
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• pp.352-358
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• 2012

In this study, we found structure-property relationship for pressure retarded osmosis (PRO) membrane, between BPS-XX and BisA-XX having similar structure but different free volume. And this comparison was subdivided by controlling its sulfonation degree. BPS-XX and BisA-XX were prepared via a polycondensation reaction. The degree of sulfonation were 20 to 60 mol.%. And they were fabricated to membrane. Characteristics were analyzed to verify of free volume. And the results showed that increase of free volume normally lead to increase permeability and decrease selectivity in equivalent molecule structure. Finally, in the permeability-selectivity results, we conclude high permeability and selectivity membrane can be prepared by controlling molecular structure and free volume.

• Progress in Medical Physics
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• v.29 no.4
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• pp.106-114
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• 2018

This study aimed to compare the performance of previous optimization algorithms against new a photon optimizer (PO) algorithm for intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) plans for prostate cancer. Eighteen patients with prostate cancer were retrospectively selected and planned to receive 78 Gy in 39 fractions of the planning target volume (PTV). All plans for each patient optimized with the dose volume optimizer (DVO) and progressive resolution optimizer (PRO) algorithms for IMRT and VMAT were compared against plans optimized with the PO within Eclipse version 13.7. No interactive action was performed during optimization. Dosimetric and radiobiological indices for the PTV and organs at risk were analyzed. The monitor units (MU) per plan were recorded. Based on the plan quality for the target coverage, prostate IMRT and VMAT plans using the PO showed an improvement over DVO and PRO. In addition, the PO generally showed improvement in the tumor control probability for the PTV and normal tissue control probability for the rectum. From a technical perspective, the PO generated IMRT treatment plans with fewer MUs than DVO, whereas it produced slightly more MUs in the VMAT plan, compared with PRO. The PO showed over potentiality of DVO and PRO whenever available, although it led to more MUs in VMAT than PRO. Therefore, the PO has become the preferred choice for planning prostate IMRT and VMAT at our institution.

• Proceedings of the KACD Conference
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• 2003.11a
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• pp.547-547
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• 2003

The aim of this study was to compare the effects of three Ni-Ti instruments on leaning ability by evaluating the volumetric and morphological changes in the apical 6mm of the root canals before and after preparation, using three-dimensionally reconstructed root canals of extracted human teeth. Forty-five teeth were used in this study. They were opened the chambers and removed the all pulp remnants ultrasonically. Subsequently, the canal wall was coated with silver paste and prepared using ProTaper, ProFile and GT rotary files according to the manufacturers instructions. Before and after root canal preparation, all the specimens were scanned with micro computed tomography and examined the differences in dentine volume removed, canal straightening, the proportion of the unchanged area and canal transportation. Quantitative analysis revealed that instrumentation increased in canal volume ranging between 0.081 and $1.866{\;}\textrm{mm}^3$. On average, the large apical preparation produced by ProTaper demonstrated smaller proportions of unchanged surface areas compared to the two other instruments in small canals. But in large canals like maxillary central incisor, the preparation of ProTaper instruments was not enough. ProTaper instrument was tended to increase more in canal volume as compared with the other two instruments but unchanged area was no significant difference. These results showed that three instruments had similar preparation ability and micro computed tomography in combination with the coated wall of root canal using silver paste is a nondestructive and valuable tool to study root canal geometry and changes after preparations in detail.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04a
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• pp.709-711
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• 2002

볼륨렌더링(volume rendering)은 3차원의 물체 내부를 가시화하기 위한 기법이다. 여기서는 물체를 복셀(voxel)이라 불리는 미소한 입방체나 미립자의 집합으로 표현하며 의료영상 등 다양한 분야에 이용된다. 볼륨렌더링은 전통적인 렌더링 방법으로 표현할 수 없는 물체의 내부나 반투명한 물체를 표현할 수 있는 장점이 있다. 하지만 방대한 데이터를 다루기 때문에 컴퓨터의 성능이 좋아야 하고 처리시간이 오래 걸린다. 미츠비시사는 PC에서 쉬어-웝(shear-warf) 방법을 기반으로 실시간 볼륨렌더링을 할 수 있는 전용 하드웨어인 볼륨프로(VolumePro)를 발표했다. 하지만 볼륨프로는 직교투영만을 하기 때문에 투시투영을 하지 못한다는 단점을 가지고 있다. 본 논문에서는 볼륨프로의 크로핑(Cropping)을 이용한 서브볼륨(Subvo1ume)을 활용하여 투시투영에 근접한 효과를 보여주는 방법을 제안한다.

• The Korean Journal of Physiology
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• v.24 no.1
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• pp.131-144
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• 1990

It is well known that the atrial natriuretic peptide (ANP) has a prepro-hormone of 151 amino-acids which loses their hydrophobic signal peptide to form 126 amino acid prohormone. The whole prohormone is released and then cleaved by proteases into more than one circulating forms. Recently, Winters et al. (1988a, b) reported that high concentrations of N-terminal fragments of prepro-ANP $(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ were detected in human plasma. However, their physiological roles have not been established. The present study was conducted to determine whether the N-terminal fragments of pro-ANP have any effect on the renal function and to compare the effect with those of G-terminal fragments of pro-ANP The results indicate that intrarenal arterial infusions of prepro-ANP $(26{\sim}41),\;(26{\sim}55),\;(56{\sim}92)\;and\;(104{\sim}123)$ induced no significant changes in renal function. Whereas ${\alpha}-human$ ANP $(prepro-ANP,\;124{\sim}151)$ and pro-ANP caused a significant increase in urine volume, renal plasma flow, glomerular filtration rate, urinary excretions of sodium, chloride and potassium, and fractional excretion of sodium. These results suggest that the N-terminal fragments of pro-ANP are ineffective, while the C-terminal fragments retain the natriuretic and diuretic activities.

• Nutrition Research and Practice
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• v.4 no.3
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• pp.196-202
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• 2010

To investigate the neuroprotective effects of bovine colostrums (BC), we evaluate the ability of consuming BC after focal brain ischemia/reperfusion injury rat model to reduce serum cytokine levels and infarct volume, and improve neurological outcome. Sprague-Dawley rats were randomly divided into 4 groups; one sham operation and three experimental groups. In the experimental groups, MCA occlusion (2 h) and subsequent reperfusion (O/R) were induced with regional cerebral blood flow monitoring. One hour after MCAO/R and once daily during the experiment, the experimental group received BC while the other groups received 0.9% saline or low fat milk (LFM) orally. Seven days later, serum pro-inflammatory cytokine (IL-$1{\beta}$, IL-6, and TNF-${\alpha}$) and anti-inflammatory cytokine (IL-10) levels were assessed. Also, the infarct volume was assessed by using a computerized image analysis system. Behavioral function was also assessed using a modified neurologic severity score and corner turn test during the experiment. Rats receiving BC after focal brain I/R showed a significant reduction (-26%/-22%) in infarct volume compared to LFM/saline rats, respectively (P < 0.05). Serum IL-$1{\beta}$, IL-6, and TNF-${\alpha}$ levels were decreased significantly in rats receiving BC compared to LFM/saline rats (P < 0.05). In behavioral tests, daily BC intake showed consistent and significant improvement of neurological deficits for 7 days after MCAO/R. BC ingestion after focal brain ischemia/reperfusion injury may prevent brain injury by reducing serum pro-inflammatory cytokine levels and brain infarct volume in a rat model.